Efficacy of Silicon in Strengthening Antioxidant Defenses Against Fungal Pathogens in Medicinal and Aromatic Plants

Abstract

The objective of this work was to investigate the impact of silicon on the regulation of antioxidant defense mechanisms, which in turn provide resistance against different plant infections that attack medicinal plants including Alloe vera, Ocimum tenuiflorum, Tinospora cordifolia, as well as aromatic plants such as Allium cepa and Curcuma. Initially, we analyzed the overall levels of phenols, flavonoids, tannins, protein, MDA, and H₂O₂ in all 5 plants that were infected with their specific pathogenic fungus. Subsequently, we assessed the effects of treating the plants with an external chemical spray of Silicon. Moreover, we assessed the activity of antioxidant enzymes in both sick and silicon treated circumstances.  The findings of our study showed notable differences in all parameters among plants affected by fungal diseases, healthy plants treated with silicon, and infected plants treated with silicon, in comparison to the control group. The results of our study indicate that the addition of silicon (Si) before to treat fungal-infected medicinal and aromatic plants led to higher levels of antioxidant enzyme activity, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), and peroxidase (POD), compared to control, Si-treated, and pathogenic fungus-inoculated plants. Taken together, this work emphasizes the protective function of silicon in our experimental medicinal and aromatic plants against harmful fungus by enhancing the activity of antioxidant enzymes.